Implement with ground-breaking impact tool

ABSTRACT

An implement for ground breaking comprises a driving apparatus with a ground-breaking impact tool operable to reciprocate the tool in a longitudinal direction, and a cart with a planar frame having coaxial wheels at a bottom end and operating handle means at a top end. On one side of the frame are mounted guides in spaced relation to the plane of the frame. By mounting means the driving apparatus is mounted on said guides for reciprocation in parallel with the longitudinal reciprocation direction of the tool and in parallel with the plane of the frame. Biasing means yieldingly counteract such reciprocation of the driving apparatus in relation to the guides. Control means for controlling the operation of the driving apparatus are mounted on the handle means.

United States Patent inventors Appl. No.

Filed Patented Assignee Priority IMPLEMENT WITH GROUND-BREAKING IMPACT TOOL 7 Claims, 4 Drawing Figs.

U.S. Ci 173/24, 173/46, 299/37 Int. Cl E0lc 23/09 Field of Search l73/22, 24, 46; 299/37 [56] References Cited UNITED STATES PATENTS 1,574,814 3/1926 Hansen 299/37 X l,587,949 6/1926 Hansen 299/37 X 2,904,320 9/1959 Salisbury et al 173/24 Primary Examiner-Ernest R. Purser Attorney-John Lezdey ABSTRACT: An implement for ground breaking comprises a driving apparatus with a ground-breaking impact tool operable to reciprocate the tool in a longitudinal direction, and a cart with a planar frame having coaxial wheels at a bottom end and operating handle means at a top end. On one side of the frame are mounted guides in spaced relation to the plane of the frame. By mounting means the driving apparatus is mounted on said guides for reciprocation in parallel with the longitudinal reciprocation direction of the tool and in parallel with the plane of the frame. Biasing means yieldingly counteract such reciprocation of the driving apparatus in relation to the guides. Control means for controlling the operation of the driving apparatus are mounted on the handle means.

Patented Dec. 14, 1971 3,627,064

4 Sheets-Sheet 1 Patented Dec. 14, 1971 4 Sheets-Sheet 2 Patented Dec 14, 1971 4 Sheets-Sheet 3 Patented Dec. 14, 1971 4 Sheets-Sheet 4 IMPLEMENT Wll'1l1-ll GROUND-BREAM1NG lIMPA CT T001.

1n ground-breaking operations, use is frequently made of an impact too], especially a chisel, which is mounted on a driving apparatus by which it is reciprocated in its longitudinal direction. The driving apparatus is of known type and comprises a hammer subjecting the tool to impacts. In the prior art implements of this type, the hammer is operated by compressed air, an explosive gas mixture, or by electricity. The implement with the tool mounted thereon usually is hand held by the operator who therefore is easily tired by the comparatively heavy weight of the implement and besides is exposed to harmful shocks. it is already known to mount the driving apparatus on a cart so that the operator will be relieved of much of the weight of the implement, but this does not eliminate the shoclts to which he is exposed during operation of the implement.

The present invention has for its object to relieve the operator of a large proportion of both the weight of the implement and the shocks to which he is exposed during operation, while not detracting from the efi'rciency of the tool.

The invention thus relates to an implement comprising a cart with two coaxial wheels and a structure on which there is mounted, for movement against the action of springs, a driving apparatus for a chisel or like impact tool which is mounted on said driving apparatus and is reciprocated therewith in its longitudinal direction in a plane of movement which is parallel to and spaced from the center axis of the wheels, the cart frame I being provided with operating handles and driving apparatus control means connected with the handles.

The object of the invention is realized by an arrangement according to which the structure has a substantially planar frame substantially parallel to said plane of movement and carrying at its lower end the wheels and at its upper end the operating handles and the control means, one side of said frame being provided with guides in which the driving apparatus is mounted in such manner that it is movable against spring action in the direction of movement of the tool only.

The invention will now be described in more detail in the following, reference being had to the accompanying drawings illustrating two embodiments ofthe invention.

In the drawings:

FIG. 1 is a front view, partly in section, of an implement according to this invention;

FIG. 2 is a lateral view, partly in section, according to FIG. 1;

FIG. 3 is a rear view of a bottom according to FIGS. 1 and 2;

FIG. 4 is a lateral view, partly in section, of another embodiment of the invention.

The implement illustrated in F108. 1-3 comprises a structure mounted on two coaxial wheels 1 and having a substantially planar frame consisting of two tubular parallel side bars 2, a crossbar 3 interconnecting the lower ends of said side bars and carrying the wheels 1, and a handlebar d interconnecting the upper ends of said side bars 2. The bars 2 may be straight along their entire length or, as shown in the drawings, they may be slightly curved at their upper ends so that the handlebar i will be more conveniently positioned. As will appear from the drawings, the wheels 1 may preferably be equipped with pneumatic rubber tires for damping the vibrations arising during operation.

The frame M and the wheels 1 together constitute a cart for supporting a driving apparatus 5 and a ground-breaking impact tool, for instance a chisel 6, supported by said driving apparatus. The cart frame has a slide for supporting the driving apparatus 3 and the tool 6, said slide consisting of two bars 7 displaceably mounted in the frame tubes 2 and carrying a support plate 6 by means of stays 9 which are mutually reinforced by cross stays 10 and 11 and extend between the bars 7 and the plate 3 as well as through longitudinal slots 12 provided in the frame tubes 2. The slide 7-11 thus is reciprocable in the longitudinal direction of the parallel frame tubes 2, and

of the implement portion of the implement the upper ends of the slide bars 7 are connected by springs 13 with the frame 2-4 at the handle end thereof. The springs 13 are sufficiently strong for normally holding the slide 7-11 and the parts supported thereby raised to the upper ends of the slots 12. The cross stay 11 of the slide has a lug 14 which is resiliently connected by a spring 15 with a pedal 16 mounted on the crossbar 3 of the frame by means of a shaft 17. By actuating the pedal 16, the'operator' can move the slide 7-11 resiliently downwards on the frame 2-4.

The support plate 8 of the slide 7-11 extends arcuately around the driving apparatus 3 and is provided at its ends with tubular guides 18 substantially paralllel to the frame tubes 2. 1n the guide tubes 18 there are mounted two longitudinally displaceable bars 19, the upper ends of which project from said guide tubes 18 and carry upwardly open bearing seats 2. for accommodating the transverse handlebar 21 with which a driving apparatus 3 of the type here concerned is equipped. For retaining the handlebar 21 in the seats 20, a latch 22 is mounted on one seat 26 and can be clamped, by means of a clamping bolt 23, to the other bearing seat 20 in a position covering the bearing seats and the handlebar 21. The lower ends of the bearing seats 20 have a support washer 24, and the upper ends of the guide tubes 18 are enlarged to constitute a seat 25. A thick-walled rubber ring .26 is interposed between the support washer 24 and the seat 25. At the lower ends of the bars 19, which project from the guide tubes, there is mounted correspondingly a support washer 27 abutting against the lower end of a thick-walled rubber ring 28, the upper end of which rests against an enlarged seat 29 at the lower end of the guide tubes 18. The lower ends of the bars 19 are threaded to receive nuts 36 for clamping the rubber rings 26, 28 between the respective support washers 24, 27 and the respective seats 25, 29. The lower ends of the bars 19 also carry a yoke 31 extending between the bars 19 and clamped thereto by means of nuts 32. A clamp .34 is secured to the yoke 31 by means of bolts 33 and clamps the lower end of the driving apparatus .5 to the yoke 31 so that the longitudinal axis of the driving apparatus 3 and thus the direction of movement of the chisel 6 are substantially parallel to the guide tubes 18 and the frame tubes 2.

The driving apparatus 5 illustrated in the drawings is of the known type where a hammer (not shown) within the driving apparatus is reciprocated by compressed air and subjects the chisel 6 to impacts in the longitudinal direction thereof. The compressed air is supplied to the driving apparatus 5 from a source (not shown) by means of a hose 35 and a control valve 36 mounted on the driving apparatus and operable by a handle 37 disposed on the handle 21 of the driving apparatus. The handle 37 is connected via a rod 38 to a handle 39 disposed on the handlebar d of the cart so that the operator can easily control the supply of compressed air to the driving apparatus 5 without letting go of the handlebar 4.

During operation of theimplement according to the invention, the operator grasps the handlebar 4 and treads on the pedal 16 so that the slide 7-11 is resiliently moved downwards and the point of the chisel 6 is urged against the ground. The operator then starts the driving apparatus by actuating the handle 39. The chisel 6 now begins to effect a hammering motion in its longitudinal direction and is driven into the ground. The vibrations of the driving apparatus 3 in the longitudinal direction of the chisel, which are caused by the hammering motion, are absorbed and partly dampened by the reciprocating movement of the bars 19 rigidly connected with the driving apparatus in the guide tubes 13, and] during this movement the rubber rings 26, 28 are alternatingly deformed, thereby absorbing a major proportion of the vibratory energy. A minor proportion of the vibrations are propagated to the slide 7-11 and cause the springs 13, 15 to be altematingly extended and shortened, while the slide is sliding in the frame tubes 2. In this manner, the operator holding the handlebar 4 and treading on the pedal 16 is exposed to extremely moderate and dampened vibrations. The pneumatic rubber tires of the wheels 1 also contribute to dampen the vibrations.

After the chisel 6 has been driven into the ground to the desired depth, the operator, if he wishes to dislodge a piece of ground, can apply force to the handlebar 4 to tilt the entire implement, thereby causing the chisel 6 to break off a piece of ground. Sometimes, the chisel 6 may get stuck in the ground and cannot readily be withdrawn. To facilitate withdrawal, the lower ends of the frame tubes 2 can be formed as compressed air cylinders comprising a piston 40, the lower piston head 41 of which is displaceable upwardly from the closed lower end of the respective frame tube 2 to abut againstan inner guide flange 42 for the piston 40 in the respective frame tube. The lower ends of the compressed air cylinders in the frame tubes 2 may be supplied with compressed air through hoses 43 connected to a valve 44 on the handlebar 4. The valve is supplied with compressed air from the compressed air source through a hose 45 and is operable by means of a handle 46. When the chisel has gotten stuck and must be withdrawn, the operator actuates the handle 46 so that the pistons 40 are moved upwardly in the frame tubes 2 and strike the lower ends (which then are lowered from the position shown in FIG. 2) of the slide bars 7. whereby the slide 7-11 is urged upwardly by the pistons 40 and thus pulls the chisel 6 out of the ground.

Instead of a compressed air operated driving mechanism 5, I

it is of course possible to use a prior art machine of the type operated by an explosive gas mixture or by electricity. In both cases, the handle 21 of the driving mechanism is equipped with control means for controlling the operation of the machine, and such control means can be connected with operating handles on the handlebar 4 of the cart in a manner analogous to the connection between the handles 37 and 39 as described in the foregoing and illustrated in the drawings.

in the embodiment illustrated in FIG. 4, the cart is designed as in FIGS. l3, with wheels I and a substantially planar framework 2-4, but secured to the lower crossbar 3 and the frame tubes 2 is a tool support in the form of a bracket 47 having a sleeve 48 in which the tool 6 is longitudinally displaceable. As in FIGS. 1-3, slide bars 7 are longitudinally displaceable in the frame tubes 2 and connected with the frame adjacent the upper end thereof by means of springs 13. In the embodiment illustrated in FIG. 4, the driving apparatus 5 is mounted in a different manner than in FIGS. 1-3 on the slide including the slide bars 7. Thus, there extend from each slide bar 7 two stays 49, the outer ends 50 of which are directed coaxially towards each other and extend parallel to the straight portions of the frame tubes 2 to form guides for mounting the driving apparatus 5 in such manner that it will be movable against spring action in the direction of movement of the tool 6 only. On either end of the handlebar 21 of the driving apparatus 5 there is clamped a holder consisting of two identical parts 51 urged against one another and the handlebar 2] by means of bolts 52. Each holder part has a bore 53 into which project the upper and lower guide ends 50, respectively, of the stays 49. A pressure spring 54 is interposed between the guide end 50 and the bottom of the bore 53. The driving apparatus 5 thus is reciprocable on the guides 50 longitudinally of the tool 6, and the springs 54 dampen the longitudinally directed vibrations arising during operation of the tool 6.

What I claim and desire to secure by Letters Patent is:

1. An implement for ground breaking comprising a substantially planar frame having a bottom end and a top end, coaxial wheels rotatably mounted on said frame at the bottom end thereof, operating handle means mounted on said frame at the top end thereof, said frame, said wheels and said operating handle means forming a cart, guide means mounted on said frame in spaced relation to the plane of said planar frame on one side thereof, a ground-breaking impact tool, a driving apparatus holding said tool and operable to reciprocate said tool in a longitudinal direction, mounting means mounting said driving apparatus with said tool on said guide means for reciprocation substantially in parallel with the direction of longitudinal reciprocation of said tool and substantially in parallel with the plane of said planar frame, biasing means operatively connected between said driving apparatus and said guide means and yieldingly counteracting reciprocation of said driving apparatus in relation to said guide means, and control means for controlling the operation of said driving apparatus, said control means being mounted on said handle means.

2. An implement according to claim 1, comprising a slide mounting said-guide means on said frame and being movable along said frame substantially in parallel with the direction of longitudinal reciprocation of said tool.

3. An implement according to claim 2, comprising spring means connected with said slide and the top end of said frame and substantially compensating for the weight of said driving apparatus and said tool.

4. An implement according to claim 3, comprising a pedal mounted on said frame and connected with said slide for moving said slide on said frame against the action of said spring means. i

5. An implement according to claim 4 comprising elastically yielding means connecting said pedal with said slide.

6. An implement for ground breaking comprising a substantially planar frame having a bottom end and a top end, coaxial wheels rotatably mounted on said frame at the bottom end thereof, operating handle means mounted on said frame at the top end thereof, said frame, said wheels and said operating handle means fonning a cart, slide means on said frame movable along said frame in a direction of movement substantially in parallel with the plane of said planar frame and substantially at right angles to the axis of rotation of said wheels, guide means mounted on said slide means in spaced relation to the plane of said planar frame on one side thereof, a groundbreaking impact tool, a driving apparatus for holding said tool and operable to reciprocate said tool in a longitudinal direction, mounting means mounting said driving apparatus with said tool on said guide means for reciprocation substantially in parallel with the direction of longitudinal reciprocation of said tool and substantially in parallel with the direction of movement of said slide means, biasing means operatively connected between said driving apparatus and said guide means and yieldingly counteracting reciprocation of said driving apparatus in relation to said guide means, control means for controlling the operation of said driving apparatus, said control means being mounted on said handle means, and actuable power means on said frame for moving said slide means on said frame in a direction towards the top end of said frame.

7. An implement for ground breaking comprising a substantially planar frame having a bottom end and a top end, coaxial wheels rotatably mounted on said frame at the bottom end thereof, operating handle means mounted on said frame at the top end thereof, said frame, said wheels and said operating handle means forming a cart, guide means mounted on said frame in spaced relation to the plane of said planar frame on one side thereof, a ground-breaking impact tool, a driving apparatus holding said tool and operable to reciprocate said tool in a longitudinal direction, mounting means mounting said driving apparatus with said tool on said guide means for reciprocation substantially in parallel with the direction of longitudinal reciprocation of said tool and substantially in parallel with the plane of said planar frame, biasing means operatively connected between said driving apparatus and said guide means and yieldingly counteracting reciprocation of said driving apparatus in relation to said guide means, tool support means mounted on said frame at the bottom end thereof and slidably engaging said tool for guiding said tool during its longitudinal reciprocation. 

1. An implement for ground breaking comprising a substantially planar frame having a bottom end and a top end, coaxial wheels rotatably mounted on said frame at the bottom end thereof, operating handle means mounted on said frame at the top end thereof, said frame, said wheels and said operating handle means forming a cart, guide means mounted on said frame in spaced relation to the plane of said planar frame on one side thereof, a ground-breaking impact tool, a driving apparatus holding said tool and operable to reciprocate said tool in a longitudinal direction, mounting means mounting said driving apparatus with said tool on said guide means for reciprocation substantially in parallel with the direction of longitudinal reciprocation of said tool and substantially in parallel with the plane of said planar frame, biasing means operatively connected between said driving apparatus and said guide means and yieldingly counteracting reciprocation of said driving apparatus in relation to said guide means, and control means for controlling the operation of said driving apparatus, said control means being mounted on said handle means.
 2. An implement according to claim 1, comprising a slide mounting said guide means on said frame and being movable along said frame substantially in parallel with the direction of longitudinal reciprocation of said tool.
 3. An implement according to claim 2, comprising spring means connected with said slide and the top end of said frame and substantially compensating for the weight of said driving apparatus and said tool.
 4. An implement according to claim 3, comprising a pedal mounted on said frame and connected with said slide for moving said slide on said frame against the action of said spring means.
 5. An implement according to claim 4 comprising elastically yielding means connecting said pedal with said slide.
 6. An implement for ground breaking comprising a substantially planar frame having a bottom end and a top end, coaxial wheels rotatably mounted on said frame at the bottom end thereof, operating handle means mounted on said frame at the top end thereof, said frame, said wheels and said operating handle means forming a cart, slide means on said frame movable along said frame in a direction of movement substantially in parallel with the plane of said planar frame and substantially at right angles to the axis of rotation of said wheels, guide means mounted on said slide means in spaced relation to the plane of said planar frame on one side thereof, a ground-breaking impact tool, a driving apparatus for holding said tool and operable to reciprocate said tool in a longitudinal direction, mounting means mounting said driving apparatus with said tool on said guidE means for reciprocation substantially in parallel with the direction of longitudinal reciprocation of said tool and substantially in parallel with the direction of movement of said slide means, biasing means operatively connected between said driving apparatus and said guide means and yieldingly counteracting reciprocation of said driving apparatus in relation to said guide means, control means for controlling the operation of said driving apparatus, said control means being mounted on said handle means, and actuable power means on said frame for moving said slide means on said frame in a direction towards the top end of said frame.
 7. An implement for ground breaking comprising a substantially planar frame having a bottom end and a top end, coaxial wheels rotatably mounted on said frame at the bottom end thereof, operating handle means mounted on said frame at the top end thereof, said frame, said wheels and said operating handle means forming a cart, guide means mounted on said frame in spaced relation to the plane of said planar frame on one side thereof, a ground-breaking impact tool, a driving apparatus holding said tool and operable to reciprocate said tool in a longitudinal direction, mounting means mounting said driving apparatus with said tool on said guide means for reciprocation substantially in parallel with the direction of longitudinal reciprocation of said tool and substantially in parallel with the plane of said planar frame, biasing means operatively connected between said driving apparatus and said guide means and yieldingly counteracting reciprocation of said driving apparatus in relation to said guide means, tool support means mounted on said frame at the bottom end thereof and slidably engaging said tool for guiding said tool during its longitudinal reciprocation. 